A few months ago, I wanted to insert a double backslash into a Confluence wiki page. This isn't as odd as it sounds; Windows network file paths begin with \\Foo\. Since backslashes are of course an escape char, you usually have to use \\\\ to get \\ to output. But, in Confluence, this outputs two newlines. Yes, double-backslash is the symbol for a newline.

Counter-intuitive, yes, but no worse than that so long as there's another symbol you can use for when you do need a double-backslash. But, the thing is, there isn't. When Confluence was first designed, they used up their only escape char with their nonstandard newline symbol. This is, their support staff informed me, a deep-rooted and unchangeable aspect of how Confluence works. It's not a bug, because it will never be changed.

This should give you the gist of what Atlassian is like.